Jump to content

Please help me figure out the correct crystal for this Benrus wrist alarm. I'm pulling my hair out!


Recommended Posts

Hello, I'm absolutely pulling my hair out finding a replacement crystal for this watch. Case says style # 6810.

 

The original crystal was fine but I made a big oopsie and took a huge chunk out of the edge of it, and so have been trying to replace it. After searching my inventory I found an original PA429-40 Crystal for the "Benrus 276-6810 Elegance"M" and "P" Wristalarm series for reflector ring" but when I went to put the old reflector ring into that new one the ring was too large and I cracked the rim (dang it). Since the package wasn't sealed I thought maybe it was a fluke and someone had put the wrong crystal in there. So I went online and bought a new sealed PA429-40 crystal and it too is too small to fit the ring.

Measuring the original vs the new one, the original is overall larger. I can't figure out what the actual correct crystal is though.

(Photo of crystal with a big chunk out of the edge is the inner diameter of the original, other crystal measurement shown is of "replacement".

Without the exact right crystal the case will not stay closed because it's pressure fit. I'm out of ideas and really could use some help on this.

PXL_20221213_130255826.jpg

PXL_20221213_130313237.jpg

PXL_20221213_130346970.jpg

PXL_20221213_130329154.jpg

PXL_20221213_130351132.jpg

PXL_20221213_130400621.jpg

PXL_20221213_130654038.jpg

Link to comment
Share on other sites

21 hours ago, Max50916 said:

Without the exact right crystal the case will not stay closed because it's pressure fit

Okay so what you're basically saying is this isn't your normal crystal. In other words this is one of those strange crystals that also functions as an integrated part of the case to hold the whole thing together.

I don't suppose the crystal number is the same as the number on the case like here for instance

https://www.ebay.com/itm/125623627474

Another option is just to email the manufacture and ask. They should have better reference material and worse case they can do a custom crystal

https://www.gssupplies.com/crystal-catalogs/

 

 

Edited by JohnR725
Link to comment
Share on other sites

5 hours ago, JohnR725 said:

Okay so what you're basically saying is this isn't your normal crystal. In other words this is one of those strange crystals that also functions as an integrated part of the case to hold the whole thing together.

I don't suppose the crystal number is the same as the number on the case like here for instance

https://www.ebay.com/itm/125623627474

Another option is just to email the manufacture and ask. They should have better reference material and worse case they can do a custom crystal

https://www.gssupplies.com/crystal-catalogs/

 

 

Yes exactly. Ok this one already has the tension ring inside so perhaps it's the correct one! We shall see. Thank you!

Link to comment
Share on other sites

On 12/14/2022 at 5:19 AM, JohnR725 said:

Okay so what you're basically saying is this isn't your normal crystal. In other words this is one of those strange crystals that also functions as an integrated part of the case to hold the whole thing together.

I don't suppose the crystal number is the same as the number on the case like here for instance

https://www.ebay.com/itm/125623627474

Another option is just to email the manufacture and ask. They should have better reference material and worse case they can do a custom crystal

https://www.gssupplies.com/crystal-catalogs/

 

 

Update: Eureka!!! For whatever reason this one worked perfectly but two attempts with the GS would not. Thanks so much for finding this, don't know how I didn't see this version when I was searching on ebay before. 

PXL_20221219_160832696~2.jpg

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Similar Content

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • I have read some suggestions that it can cause wear , particularly on the fork horns of a fully treated pallet fork. I've had half a kilo of steriac acid powder on a shelf for almost a year now, might have a little play today with a heater and a jar.  I think its because it gets into their cleaning solutions Mike. Theirs or anyone else's that services the watch next time, or if they need to strip back and rebuild. Could preclean but thats all time for a pro.
    • As I'm only cleaning watches in small numbers at home, I pre-clean any significant deposits of old grease and oil before using the cleaning solutions. I scrape off deposits with pegwood and Rodico, and if really dirty, wash parts in naphtha with a brush.  So I'm happy using DX, but can understand why it's avoided by the pros.
    • I think attaching a nut to the lid to pull it off is the least destructive, any damage damage on the outside is going to an easier fix than any created when trying to push it out from the inside. Scratching up the inside of the lid , mainspring or arbor bearing will be risk. Just my opinion.
    • yes the things we read in the universe I did see some where it was either difficult to clean off or it contaminated the cleaning fluid there was some issue with cleaning. I was trying to remember something about grease where as opposed to a substance of a specific consistency they were suggesting it had a base oil with something to thicken it. That conceivably could indicate that the two could separate and that would be an issue. But there is something else going on here that I had remembered so I have a link below and the description of the 9501 notice the word that I highlighted? Notice that word appears quite a bit on this particular page like 9415 has that property all so they 8200 mainspring grease and that definitely has to be mixed up when you go to use it because it definitely separates. just in case you didn't remember that nifty word there is a Wikipedia entry. https://en.wikipedia.org/wiki/Thixotropy   https://www.moebius-lubricants.ch/en/products/greases I wonder if what you're seeing is the boron nitride left behind after cleaning. In other words it's the high-pressure part of the grease and it's probably embedding itself into the metal which is why it doesn't clean off and shouldn't be a problem?
    • Yes and no. I use Moebius 9501 synthetic grease and it is significantly runnier than the Moebius 9504 synthetic grease (and I assume Molykote DX) that I previously used. I haven't seen 9504 spread and it is in my opinion the best grease money can buy. However, my current method of cleaning doesn't remove it from the parts, so that's why I have decided to use the 9501 instead. I believe I read somewhere that Molykote DX too is difficult to clean off. Thinking about it, I'm pretty sure my 9501 grease which expired in June 2022 is runnier now than it was when it was new, but whether new or old it always needs to be stirred before use. So, that's why I treat the parts of the keyless works, cannon pinion, etc. with epilame. That was very thoughtful of you and something that had completely passed me by. Not sure what the epilame will do when it wears off in a non-oiled hole. Anyone?
×
×
  • Create New...